A Juno radio-occultation view of Jupiter's ionosphere with implications for magnetosphere-ionosphere coupling

Jupiter's ionosphere provides the electrodynamic boundary for magnetosphere–ionosphere (M-I) coupling, shaping how field-aligned currents close, how momentum is exchanged through ion-neutral drag, and how magnetospheric energy input is distributed in the upper atmosphere. Despite its central role, the vertical structure and variability of Jupiter’s electron density remain incompletely characterized, particularly at high latitudes associated with auroral processes.

We present an overview of electron density profiles derived from the full set of Juno radio occultations processed to date, complemented by neutral atmospheric profiles retrieved along the same limb geometries. This dataset enables a systematic assessment of how key ionospheric characteristics - peak electron density, peak altitude, and vertically integrated content - vary with local time, latitude, and illumination. By examining ionospheric structure in the context of the co-retrieved neutral atmosphere, we investigate how variations in scale height and background state may shape conductivity profiles relevant to current closure and the efficiency of M-I coupling.

We place particular emphasis on occultations sampling auroral and high-latitude regions, where changes in electron density are expected to modulate the coupling between magnetospheric forcing and thermospheric response. Overall, these profiles provide an observational basis for ionosphere-thermosphere modeling and for the conductivity and boundary assumptions commonly used in M-I coupling studies.